Metallic reagent

ABSTRACT

A reagent suitable for use as a catalyst comprises a first metal species substrate having a second reduced metal species coated thereon, the second reduced metal species being less electropositive than the first metal. Methods of manufacture are also provided.

FIELD OF THE INVENTION

The present invention relates to a metallic reagent and methods ofmaking the reagent.

BACKGROUND OF THE INVENTION

Activation energy is the minimum energy required to convert thereactants of a chemical reaction into products. When the activationenergy is small, kinetic energy from collisions between the reactantscan provide the energy required to surmount the activation energybarrier. Conversely, when the activation energy is high, the reactionmay require an input of energy, such as heat, and/or alternate means toobtain the products.

Catalysts are often used to facilitate completion of the reaction and/orincrease the reaction rate. They function by providing an alternativereaction path having a lower energy of activation. The selection of thecatalyst may be based on thermal stability of the reactants andproducts, energy savings, the raw material, labor and plant processcosts, relative yields, and environmental factors. Metals andparticularly transition metals are employed as catalysts in a variety ofreactions such as the formation of ammonia, production of sulfuric acid,hydrogen addition across alkene or alkyne bonds, ring opening, andpolymerization reactions.

Despite their broad uses, use of some metal catalysts still requiresthat a reaction be performed under extreme conditions because thecatalyst alone does not provide a sufficiently low activation energy.Addition of extreme heat and/or pressure generates sufficient kineticenergy to increase the fraction of molecules whose kinetic energyexceeds the activation energy and thereby increase the reaction rate.Also, the use of certain metal catalysts can be cost prohibitive. Forexample, in some polymerization reactions, zerovalent platinum orpalladium may be successfully used to alter the activation energy, butthe expense and difficulties of acquiring these metals may makeperforming the reaction impractical for large scale applications.

It would be desirable to provide a reagent that has enhanced reactivity,is cost effective, and is easy to manufacture and use. It would also bedesirable to have a metal reagent that is able to integrate with andenhance current metal catalysis methods.

It would be further desirable to provide methods to oligomerize andpolymerize monomers. It would also be desirable that such methods beconducted at lower temperatures and under atmospheric pressure. It wouldalso be desirable if the methods were cost effective, used inexpensivestarting materials, and minimized reaction time.

SUMMARY OF THE INVENTION

The present invention provides a reagent suitable for use as a catalystcomprising a first metal species substrate having a second reduced metalspecies coated thereon. The second reduced metal species is lesselectropositive than the first metal. In various embodiments, thereagent is in the form selected from the group consisting of spheres,particles, turnings, blocks, beads, mesh, or combinations thereof.

The present invention also provides a method of making a reagentcomprising: providing a metal substrate; and applying a lesselectropositive metal onto the substrate. The second metal forms atleast one island on the substrate.

The present invention also provides a method of making a reagentcomprising refluxing a metal substrate in the presence of a lesselectropositive metal salt and a solvent.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

The present invention provides a reagent comprising a first metalspecies substrate having a second reduced metal species coated thereon,where the second reduced metal species is a less electropositive metalthan the first metal. As used herein, electropositive refers to therelative standard electrode potentials of the elements. The metals andmetallic elements have standard electrode potentials ranging from 3.05(lithium—most electropositive) to −2.65 (fluorine—leastelectropositive), with reference to H₂ ion as the zero potential couple.The more electropositive metal will reduce the less electropositivemetal. For example, an electropositive or active metal, such as zinc(0.76), will tend to reduce a less-active or noble metal, such as copper(−0.34) or silver (−0.80). While not intending to be bound by aparticular theory, it is believed that the difference inelectropositivity provides a surprisingly effective catalysis ascompared to the catalysis action of the metal substrate material or thesecond reduced metal species material alone.

The first metal species forms the core of the reagent and is selectedfrom the group consisting of alkali metals, alkaline earth metals,transition metals, and metalloids. Various alloys of these metals arealso highly suitable in various embodiments. The alloys may be anydesirable combination of metals, for example, a Mg alloy according tovarious embodiments refers to Mg combined with any other metal, such asan Mg/La alloy. Preferred transition metals are from the firsttransition series (Sc through Zn) and the second transition series (Ythrough Cd). Preferably, the metal substrate is Mg, V, Cr, Zn, Al, Li,Na, K, Be, Ca, Sr, Ba, Ti, Si, and alloys thereof. In various preferredembodiments, the metal substrate is Mg, V, Cr, Al, Zn, or alloysthereof. In a preferred embodiment, the metal substrate comprises Mg oralloys thereof.

The second metal species is preferably selected from the groupconsisting of transition metals from the first, second, and thirdtransition series and alloys thereof. It is understood that the secondmetal may also include any alkali or alkaline earth metal, transitionmetal, or metalloid that is less electropositive than the metalsubstrate. This includes using a substrate and a second metal fromwithin the same chemical family, such as two transition metals or twoalkaline earth metals. The second metal is in reduced form on thesubstrate. Preferably, the second metal species is Ni, Co, Cu, Ti, V,Re, Ru, Rh, Ir, Pd, Pt, Ag, Au, or alloys thereof. In various preferredembodiments, the second metal species is Ni, Co, Cu, or alloys thereof.

The second metal species is disposed in reduced form on the substratecore. In various embodiments, the second metal species coats the entiremetal substrate core or it covers discrete regions of the core includingislands or spots. The second metal species may also be disposed ascontinuous straight or curved lines, dashed lines, or in a weave orpattern. In various embodiments, the reagent comprises from about 95% toabout 99.9% of the first metal species by weight and from about 0.1% toabout 5% of the second metal reduced species by weight. Preferably, thereagent comprises about 1% of the reduced species by weight.

In a preferred embodiment, the first metal substrate comprises Mg andalloys thereof and the second metal is selected from the groupconsisting of Ni, Co, Cu, and alloys thereof. In an alternate preferredembodiment, the first metal substrate is V or alloys thereof and thesecond metal is selected from the group consisting of Ni, Co, Cu, andalloys thereof.

The metal substrate is of a size suitable for use as a catalyst. Invarious embodiments, the reagent is in the form of a mesh, a powder, ablock, beads, spheres, or turnings. These forms of metal maximizesurface area that may be exposed to reactants. Surface area of the metalreagent may range from about 5 nm to about 5 mm. An average dimension(length, diameter, etc.) is less than about 1000 μm. In variousembodiments, the average dimension is less than about 500 μm or fromabout 100 μm to about 400 μm. For example, in an embodiment utilizing amesh substrate, a preferred size is 40 to 80 mesh. The surface area ofthe reagent may correlate with the reaction rate. A low surface areareagent tends to catalyze the reaction slower than the same reagenthaving a greater surface area. A mixture of reagents having differentsurface areas allows the user to tailor the reaction rate. Furthermore,combinations of metal substrate types and surface areas may also beused, which may provide greater control of catalysis, particularly thereaction rate and temperature.

Methods of Making a Reagent

Methods of making a reagent according to various embodiments of thepresent invention are also provided. The method comprises providing ametal substrate and applying a second metal onto the substrate using themetals and metal combinations disclosed earlier herein.

Suitable application techniques include immersion plating, chemicalconversion, electroless plating, mechanical plating, detonation gun,plasma arc, vacuum plasma, wire arc, chemical vapor deposition, electronbeam evaporation, ion beam assisted deposition, ion implantation, ionplating, physical vapor deposition, sputtering, and vacuum metallizing.

In one embodiment, the application is by immersion plating. Immersionplating involves depositing the second (less electropositive) metal ontothe metal substrate without aid of an external electric current. A saltof the less electropositive metal is put into a solution and thesolution is contacted with the first metal substrate in suitable form.To illustrate for a cobalt/nickel reagent, cobalt chloride salt, or anyother suitable cobalt salt, is put into solution. Suitable solventsinclude tetrahydrofuran, dimethoxyethane, or other compounds which areable to dissolve the metal salt to some extent without being consumed inthe reaction. The solution is contacted with the nickel substrate. Asthe less electropositive cobalt ions are drawn to the moreelectropositive nickel substrate, the cobalt deposits onto the nickelsubstrate forming the reagent.

In another embodiment, the reagent is made by refluxing the metalsubstrate in the presence of the second metal and a solvent, preferablyan organic solvent. Non-limiting examples of suitable organic solventsinclude tetrahydrofuran and dimethoxyethane. In a highly preferredembodiment, a Soxhlet extractor including a flask, a condenser tube, anda thimble is used. In such an embodiment, the metal substrate is placedinto the flask with a solvent. A thimble containing the second metalsalt is placed between the flask and the condenser tube. Refluxing thesolution from the flask up to the condenser and down through the thimbleinto the flask again washes the salt in the thimble into the flask wherethe second metal deposits onto the metal substrate. While not intendingto be bound by a particular theory, it is believed that the use of theSoxhlet extractor provides optimal coating results and concentrates thereagent in the flask. It is particularly useful when a minimally solublemetal salt is used as the reagent. Optionally, the reagent is washed andprepared to remove any residue from formation.

One method of forming the catalyst particles in situ is illustrated inthe following. Particles made of the first metal are added to acomposition containing at least one solvent molecule. The solventcomposition is then heated and stirred in the presence of the metalsubstrate. A salt containing the second metal is then added to thesolvent molecule composition containing the first metal particles. Theaction of heat and stirring causes the second metal to be reduced anddisposed onto the surface of the first metal particles. The first metalforms a core onto which the second metal is disposed, preferably atleast in part as islands.

The metal substrate may optionally be pre-treated before the applicationof the second metal species islands. For example, in many cases it isdesirable to pre-treat the substrate to remove a passivation layer thatbuilds up on the metal substrate upon exposure to oxygen. In variousembodiments pre-treatments involves subjecting the surface to reducingconditions, which renders it more electrochemically active.Alternatively or additionally, current cleaning methods are used. Theseemploy cathodic cleaning where electrical current (which is on the orderof about 4 A/cm² in an exemplary embodiment) is applied to theconductive substrate which is in contact with an electrolyte tofacilitate the generation of gas bubbles at the surface. Otherpre-treating methods include mechanical abrasion of the surface, orcleaning the substrate with commercially available alkaline cleaners, orpickle liquors. The metal substrate may also be treated with an acidicsolution designed to convert the metal oxides to soluble constituentsthat may be readily removed from the surface. Ultrasonic agitation andhigh shear mixing may also be used to remove the adherent oxide. Inpreferred embodiments, the oxide layer is removed by heating the metalsubstrate to a temperature above the boiling point of the solvent.Adding the solvent to the heated metal substrate volatilizes the solventand explodes the oxide passivation layer off of the substrate.

Additional pre-treatment or preparation steps may be performed such asmetal etching before applying the second reduced metal to increase thesubstrate surface area. Subsequent treatment steps such as forced-aircooling may also be employed. One skilled in the art understands thatvariations in any particular pretreatment may be made or other variouspretreatments of metals may be used.

Dimeric and Polymeric Reaction Products

Methods for synthesizing dimeric or higher polymeric reaction productsof nitrogen containing aromatics are also provided. The method comprisescontacting a composition containing the nitrogen aromatic with acatalyst composition described above. The nitrogen aromatic compositioncomprises a compound or a mixture of compounds represented by thestructure

whereinX is —N— or —CR²—, andR¹, R², and R³ are independently selected from the group consisting ofhydrogen, alkyl, aryl, heterocyclyl, heteroaryl, and cycloalkyl groups,the groups other than hydrogen having from 1 to 20 carbons. The nitrogenaromatics function as polymerizable monomers. In various embodiments,the compositions further comprise solvent molecules other than thenitrogen aromatic monomer compounds.

The catalyst composition is in particulate form and contains a firstmetal substrate having a second reduced metal coated on the substrate.In preferred embodiments, the first metal is selected from the groupconsisting of Mg, V, Cr, Al, Vn, and alloys thereof and the second metalis selected from the group consisting of Ni, Co, Cu, and alloys thereof.

The products of the method are dimeric, oligomeric, or polymericdepending on the reaction conditions. Oligomeric and polymeric productscan be homopolymers or copolymers depending on the choice of startingmonomers. In a preferred embodiment, polymeric products are homopolymersof pyridine, or copolymers of pyridine and other nitrogen aromaticmonomers. Preferably copolymers have greater than 50 mole % pyridine.

In another embodiment, the invention provides methods for producingdimeric aromatic compounds. The methods involve contacting a compositioncontaining a nitrogen aromatic compound with a catalyst composition asdiscussed above. The reaction is carried out for a time sufficient tofavor formation of a dimeric product over a polymeric product. Preferredaromatic compounds for use in this embodiment of the invention includethe compounds (I) described above where R¹ is hydrogen. In a preferredembodiment, the nitrogen aromatic compound reaction product is4,4′-bipyridyl.

In another embodiment, the invention provides a method for polymerizingpyridine, comprising contacting a composition containing pyridine with acatalyst composition such as those described above. The catalystpreferably contains a first metal and a second metal, with the firstmetal selected from the group consisting of Mg, V, Al, Cr, V, and alloysthereof, and the second metal selected from the group consisting of Ni,Co, Cu, and alloys thereof. In various embodiments, the catalyst is inthe form of particles having an average dimension less than 500 μm. Asstated above herein, the catalyst is preferably in particulate formhaving sufficient surface area to catalyze the reaction, particularlypolymerization. A preferred first metal is magnesium and a preferredsecond metal is nickel.

In various embodiments, the method is performed by bringing the catalystcomposition into contact with the composition containing the nitrogenaromatic monomers. In other embodiments, the catalyst is formed in thepresence of the monomer composition. For example, particles comprisingthe first metal are added to a pyridine composition, and a saltcontaining the second metal is added to the pyridine. Heating andstirring of the pyridine composition causes in situ formation of thecatalyst and polymerization of the pyridine. In a preferred embodiment,the salt containing the second metal is added to the reaction mixture byway of Soxhlet extraction.

In one aspect, the step of contacting catalyst compositions of theinvention with nitrogen containing aromatic compounds as describedaffords a general route to dimeric, oligomeric, and polymeric products.The dimeric products are represented by the structure

whereinX is —N— or —CR²—;R² and R³ are independently hydrogen or an alkyl, aryl, cycloalkyl,heterocyclyl, or heteroaryl group containing 1 to 20 carbon atoms.Dimeric products arise from the action of the catalyst on nitrogenaromatics wherein R¹ is hydrogen as discussed above. In a preferredembodiment, X is —CR²— and the dimeric products are bipyridylderivatives.

Oligomeric and polymeric reaction products of the invention arerepresented by the structure

wherein R¹, R³, and X are as described above and n is 2 or greater. Itis to be understood that formulas such as (III) represent the polymericcore or repeating unit of the polymeric or oligomeric reaction product,and is a conventional representation of a polymeric material based on2,6-polymerization of pyridine or pyrimidine derivatives.

As noted, when R¹ is hydrogen, the nitrogen aromatic starting materialcan form dimeric products as well as 2,6-oligomeric or polymericproducts. In one aspect, the reaction product obtained from the reactionand the relative ratio of dimeric to oligomeric or polymeric productsdepends on a variety of parameters such as time and temperature ofreaction. In one aspect, dimerization to form the dimeric products isreversibly formed in a first fast step. Formation of oligomeric andpolymeric 2,6-products on the other hand is slower kinetically, but morethermodynamically favored. In this aspect, longer reactions time tend tofavor the formation of oligomeric and polymeric reaction products. Thus,in one aspect of the invention, dimeric reaction products are preparedby reacting for relatively short times, whereas longer reaction timesfavor the formation of the polymeric and oligomeric species.

In various embodiments, formation of oligomeric and polymeric productscan also be favored by carrying out the reaction in a solvent in whichthe polymeric products are not soluble. As polymeric compounds areformed they precipitate out of solution and are not further availablefor kinetically favored dimerization. Thus, the reaction can be carriedout in the presence of the monomeric nitrogen aromatics as a solesolvent or in non-reactive solvents such as without limitationacetonitrile, toluene, xylene, 2,6-substituted pyridines andpyrimidines, and the like.

The nature of the polymeric products formed depends on the compositionand the relative reaction rates of nitrogen aromatics in the nitrogenaromatic composition that is contacted with catalysts of the invention.The products can be homopolymers or copolymers. In preferredembodiments, the reaction products are polypyridine or copolymers ofpyridine with other pyridine and pyrimidine derivatives such as givenabove. In preferred embodiments, copolymers contain a major amount ofpyridine and a minor amount of other monomers. To illustrate preferredpolymers contain 50 mole % or more of pyridine, preferably 75 mole % ormore, and more preferably 90 mole % of pyridine or greater. Theremainder of the monomeric units are made of nitrogen aromatics otherthan pyridine. Polypyridine and other nitrogen aromatic polymers areuseful for example, as light emitting devices, electroluminescentdisplays, and in semiconductors.

The n given in the structure of the oligomeric and polymeric materialsabove ranges from 2 to about 500,000. When n is in the lower part ofthis range, the compounds an be described as oligomeric. When n isgreater than about 5 or 10, the compounds are generally referred to aspolymeric. The reaction product mixture resulting from contacting thenitrogen aromatic compounds with the catalyst of the invention generallycontains molecular species characterized by a range of values n, as isfamiliar to those of skill in the art of polymerization. As is usual inthe polymer field, the molecular weight or size distribution of thereaction products can be defined by a molecular weight that depends on nand a molecular weight distribution characterized by a polydispersity.

The catalyst is based on compositions containing at least one lessactive metal and at least one more active metal. A less active metal isone having a relatively higher reduction potential. In one aspect, thecatalyst used for polymerizing the nitrogen aromatics contains a firstmetal selected from Mg, V, Al, Cr, V, and alloys thereof and a secondmetal selected from Ni, Co, Cu, and alloys thereof. Preferably, thecatalyst is in the form of particles having an average dimension of lessthan 500 μm. In various embodiments, the catalyst is in particulate formthat has sufficient surface area to catalyze the polymerization. Also invarious embodiments, the first metal forms a core of the catalyticparticles and the second metal is disposed in reduced form on the core.In preferred embodiments, the second metal is disposed on the core insuch a way as to not cover completely the core. In this embodiment, thesecond metal is present at least in part as islands of second reducedmetal on the first metal core. A preferred material for making thecatalyst is magnesium or a magnesium alloy. Magnesium metal iscommercially available in particulate form having sufficient surfacearea to be useful as catalyst of the invention when coated with a secondmetal in the way described above. In a preferred embodiment, the secondreduced metal disposed on the core is nickel.

In various embodiments, the dimerization, oligomerization, andpolymerization reactions are carried out by bringing into contact acomposition comprising the catalyst and a composition containing thenitrogen aromatic monomer materials. The catalyst and monomers can bebrought into contact in any suitable method. In a non-limitingembodiment, the catalyst particles are prepared in a separate step andadded to a composition containing the nitrogen aromatic monomericmaterials. In another embodiment, the catalyst particles are formed insitu under the reaction conditions, as discussed earlier herein. In situformation occurs when a salt of the second metal is added to acomposition containing particles of the first metal and a compositioncontaining the nitrogen aromatic compound or compounds. As the nitrogenaromatic composition is heated and stirred as detailed above, thecatalyst is formed in situ and the dimerization, oligomerization, andpolymerization reactions described above are catalyzed.

The invention has been described with respect to various preferredembodiments. Further non-limiting description is given in the examplesthat follow.

EXAMPLES Example 1

A nickel/magnesium reagent is prepared by the following protocol. Thereaction vessel components are first flushed with dry nitrogen gas andthe reaction is performed under dry nitrogen gas. 20 grams of 80 mesh Mgmetal is placed in a 250 mL 3-neck flask and approximately 140 mL ofanhydrous tetrahydrofuran (THF) is added. The flask is connected to asoxhlet extraction apparatus which has an extraction thimble containing0.5 g of anhydrous nickel bromide. The THF was refluxed for 5 days untilthe nickel bromide has entirely washed into the flask. Refluxing ishalted and the contents of the flask are isolated in a Buchner filterfunnel. The solid material is washed several times with THF until thewashings are colorless.

The product consists of discontinuous islands of nickel on the surfaceof magnesium. Chemical analysis shows that the product contains 0.4% byweight of nickel. The rest of the metal content is overwhelminglymagnesium.

Example 2

A reagent is prepared according to Example 1 substituting cobaltchloride for nickel bromide, resulting in magnesium coated with cobalt.

Example 3

All manipulations are performed in a dry inert atmosphere. 20 g of 40-80mesh magnesium is placed in the thimble of a Soxhlet extractor andwashed with anhydrous pyridine for 24 hours. The cleaned metal is thendried by passing dry nitrogen over it.

In a separate step, 0.4 g of anhydrous nickel bromide are weighed outand placed in the thimble of a Soxhlet reactor. 5.0 g of the washed anddried magnesium metal described in the preceding paragraph are placed ina 250 mL round bottom flash. Approximately 140 mL of anhydrous pyridineis added to the flask and the flask is attached to the Soxhletextractor. The flask is heated to boil (pyridine boils at 114° C.), andnickel bromide is washed into the flask from the Soxhlet extractor for 1hour. At this point, the contents of the flask are dark blue to blackand appear to be increasing in viscosity. The heating is stopped and theflask is allowed to cool. Upon cooling, the contents of the flasksolidify. The dark solid is not very soluble in alcohol, acetone, water,tetrahydrofuran, or methylene chloride. The flask is maintained atapproximately atmospheric pressure throughout the reaction.

Example 4

The preparation of a nickel magnesium catalyst is carried out as inExample 1. 1.0 g of the catalyst (containing 0.4% by weight nickel) andapproximately 140 mL of anhydrous pyridine is added to a 250 mL roundbottom flask equipped with a stirring bar and attached to a refluxcondenser. The mixture is heated to reflux with stirring. The refluxtemperature is approximately 114° C. After an incubation time of 30minutes the mixture begins to darken. After 60 minutes, the mixtureincreases substantially in viscosity and is a dark blue.

Example 5

A similar reaction is performed using 5 g of catalysts. The reaction isallowed to run for two hours. At this point the contents of the reactionvessel are completely solidified. A small amount of material identifiedas 4,4′ bipyridyl can be extracted with tetrahydrofuran, pyridine,xylene, or diethyl ether. p Although the invention has been describedabove in various exemplary aspects, it is to be understood that theinvention is not limited to the disclosed embodiments. Variousmodifications that will occur to a person skilled in the art uponreading the specification are also within the scope of the invention,which is defined in the appended claims.

1. A reagent suitable for use as a catalyst comprising: a first metalspecies substrate having a second reduced metal species coated thereon,the second reduced metal species being less electropositive than thefirst metal wherein the second metal reduced species comprises fromabout 0.1% to about 1% of the reagent by weight and further wherein thesecond metal reduced species is disposed on the first metal in a formselected from the group consisting of islands, spots, lines, dashes,weave form, or pattern form.
 2. A reagent according to claim 1, whereinthe reagent is in a form selected from the group consisting of spheres,particles, turnings, blocks, beads, mesh, and combinations thereof.
 3. Areagent according to claim 1, wherein the first metal substrate isselected from the group consisting of alkaline earth metals, alkalinemetals, transition metals, and alloys thereof.
 4. A reagent according toclaim 3, wherein the first metal substrate is selected from the groupconsisting of Mg, V, Cr, Zn, Al, Li, Na, K, Be, Ca, Sr, Ba, Ti, Si, andalloys thereof.
 5. A reagent according to claim 1, wherein the secondmetal is selected from the group consisting of transition metals andalloys thereof.
 6. A reagent composition according to claim 5, whereinthe second metal is selected from the group consisting of Ni, Co, Cu,Ti, V, Re, Ru, Rh, Ir, Pd, Pt, Ag, Au, and alloys thereof.
 7. A reagentaccording to claim 1, wherein the first metal substrate comprises Mg oralloys thereof and the second metal is selected from the groupconsisting of Ni, Co, Cu, and alloys thereof.
 8. A reagent according toclaim 1, wherein the first metal substrate comprises V or alloys thereofand the second metal is selected from the group consisting of Ni, Co,Cu, and alloys thereof.
 9. A reagent according to claim 1, wherein thereagent comprises 1% of the second metal reduced species by weight. 10.A method of making a reagent comprising: a. providing a substratecomprising a first metal; and b. applying a second metal lesselectropositive than the metal of the first metal onto the substrate,wherein the second metal is reduced to form a second metal reducedspecies and further Wherein the second metal comprises from about 0.1 %to about 1% of the reagent by weight and further wherein the secondmetal reduced species is disposed on the first metal in a form selectedfrom the group consisting of islands, spots, lines, dashes, weave form,or pattern form.
 11. A method of making a reagent according to claim 10,wherein the substrate is in a form selected from the group consisting ofin the form of spheres, particles, turnings, mesh, blocks, beads, orcombinations thereof.
 12. A method of making a reagent according toclaim 10, wherein applying a second metal is selected from the groupconsisting of immersion plating, chemical conversion, electrolessplating, mechanical plating, detonation gun, plasma arc, vacuum plasma,wire arc, chemical vapor deposition, electron beam evaporation, ion beamassisted deposition, ion implantation, ion plating, physical vapordeposition, sputtering, and vacuum metallizing.
 13. A method of making areagent according to claim 10, wherein applying a second metal is byimmersion plating.
 14. A method of making a reagent according to claim10, further comprising removing an oxide layer from the metal substrate.15. A method of making a reagent according to claim 10, wherein thefirst metal is selected from the group consisting of Mg, V, Cr, Zn, Al,Li, Na, K, Be, Ca, Sr, Ba, Ti, Si, and alloys thereof.
 16. A method ofmaking a reagent according to claim 10, wherein the second metal isselected from the group consisting of Ni, Co, Cu, Ti, V, Re, Ru, Rh, Ir,Pd, Pt, Ag, Au, and alloys thereof.
 17. A method of making a reagentcomprising refluxing a metal substrate in the presence of a metal saltand a solvent, wherein the metal salt comprises a metal lesselectropositive than the metal of the substrate and further wherein themetal of the metal salt comprises 1% or less of the reagent by weightand the metal of the metal salt is disposed on the metal substrate in aform selected from the group consisting of islands, spots, lines,dashes, weave form, or pattern form.
 18. A method of making a reagentaccording to claim 17, wherein the solvent is an organic solventselected from the group consisting of tetrahydrofuran anddimethoxyethane.
 19. A method of making a reagent according to claim 17,wherein the first metal substrate comprises a metal selected from thegroup consisting of Mg, V, Cr, Zn, Al, Li, Na, K, Be, Ca, Sr, Ba, Ti,Si, and alloys thereof.
 20. A method of making a reagent according toclaim 17, wherein the metal salt comprises a metal selected from thegroup consisting of Ni, Co, Cu, Ti, V, Re, Ru, Rh, Ir, Pd, Pt, Ag, Au,and alloys thereof.
 21. A method of making a reagent according to claim17, wherein the reagent comprises from about 0.1% to about 0.5% byweight of the less electropositive metal.